A swell paper
line graph (courtesy of MSU, University of Sussex)
diagram of a fly (courtesy of National Centre for Tactile
Graphics, University of Hertfordshire)
As visually impaired children are now being
integrated into mainstream education, more teachers are finding
themselves in the position of having to address issues of graphic
literacy ('graphicacy') with these children. This article aims
to help these teachers by providing a basic introduction to 'tactile'
graphics, that is diagrams, charts, maps, graphs and so on, that
can be felt as well as seen. In our article in Primary Science
Review, Issue No. 64, we argued that graphic literacy is now expected
of any educated adult and that primary school science teachers
are in a unique position to lay good foundations for the development
of this important communication skill.
Catering for the individual child
Sight problems vary enormously and, by taking
a little time to establish the nature of the sight problems of
the child in your class, you will be able to play to his or her
strengths. While some children have no sight at all, some can
perceive the direction of light, and some have partial sight.
You are unlikely to encounter a totally blind child in a mainstream
primary school, but you may have a partially sighted child in
your class. The child may be able to see large objects but not
text or, conversely, to see small areas of text but nothing distant.
Similarly, he or she may have tunnel vision or the opposite -
some peripheral vision but loss of central vision.
Teaching materials need to cater for these
variations. Some partially sighted children may benefit from having
things enlarged on a photocopier, while others may find that worse.
Most will benefit from high contrast between lines and background,
and from the use of strong colours. Many will also find it helpful
to supplement their limited sight by using touch, although some
may feel there is a stigma attached to this.
A child's sight history is also relevant.
Previous visual experience affects what can be comprehended through
touch. The child's understanding of distance, scale and depictions
of 3D will be affected by whether they have ever encountered and
understood such concepts visually, even at a very young age.
Production of tactile graphics
You may be able to obtain suitable tactile graphics
from the RNIB, NCTD (see end) or from a special school near you,
or you may need to make your own. It is worth knowing the pro's
and con's of the three main production methods: swell paper, thermoform,
and German film:
Swell paper. This is a special paper
coated with invisible capsules containing alcohol. A black image
is drawn or photocopied onto the paper which is then heated in
a special developer machine. The black areas absorb heat faster
than the surrounding white areas, boiling the alcohol and bursting
the capsules. The black areas 'swell' permanently and can be felt
in relief against the flat white background. Many education authorities
have a developer machine as a central resource or you can send
flat masters to the RNIB 's Raised Diagram Copying Service. The
principal advantage of the method is its speed, although one must
guard against the temptation to photocopy and raise diagrams which
are not really suited to the tactile medium. The other advantage
is the high contrast between the black and white (colour can be
added with felt pens or crayons). The principle disadvantage of
the method is the lack of variation in height.
Thermoform. This method involves
heating a thin sheet of cream-coloured plastic and vacuum-forming
it over a raised shape, using a special machine. When the sheet
is removed it retains the shape permanently in relief. Relief
mouldings of small objects can be made (e.g. keys) but more often
the method is used to produce multiple copies of master graphics
made with materials such as cardboard, string and wire. The principle
advantage of thermoform is that it allows heights up to 2 cm,
which helps make the graphic clearer. The principal disadvantages
are that producing the masters is time-consuming, the plastic
is a uniform colour and does not take felt pens effectively, and
the specialist machine is found only in establishments like special
German film. This is semi-transparent
plastic sheet which can be drawn on using an ordinary biro. The
pen leaves not just an ink trace but also a raised line. The main
advantage of this method is that it can be used interactively
to create a graphic which children can feel at different stages
of production. They can also make their own graphics. The main
disadvantages of the method are that there is little variation
in line height, and graphics quickly become tatty as the film
Choosing which graphics to 'translate'
It is advisable to adopt a very selective approach
in choosing which graphics to 'translate' into tactile form, as
the production and use of tactile graphics takes effort on the
part of the teacher and the child. Try the following three-step
1. Eliminate non-essential graphics.
Be critical of the purpose of any graphic.
Is it just there to break up the text or does it convey an essential
2. Substitute essential graphics where
Keep a scrap box of empty containers,
bits of wire, plastic lids, etc., so you can provide visually
impaired children with a 'hands-on' explanation of concepts conveyed
graphically to sighted children. (A blind child, confused by a
raised line diagram of a coiled spring, understood straightaway
when handed a coiled piece of wire.)
3. Redesign the remaining graphics
Do not get too disheartened at this prospect:
the simpler the better is a good rule of thumb. A few quick squiggles
will often produce a much more effective raised graphic than the
Translating visual graphics into tactile
When considering the design of tactile graphics
it is important to remember that touch does not allow such fine
discrimination of detail as vision. Tactile information is also
often harder to make sense of (e.g. it can be difficult to distinguish
between a foreground object and its background). Some rules of
thumb for good design are:
Focus on the essential point of the
graphic: 'less is more' really is the case here.
Do not copy and raise photographs:
substitute with text or a diagram.
Avoid line drawings where possible: e.g.
in the classic food chain diagram showing drawings of the animals,
use a word label instead.
Use filled shapes rather than outlines
(e.g. for maps) - otherwise it can be hard to know whether you
are feeling 'inside' or 'outside'.
Avoid label lines: these can get
confused with the diagram itself. Put labels on the relevant part,
or use a key.
Keep lines at least 2 mm apart.
You can get some idea of the clarity of a tactile
graphic by trying it out on someone who has not seen it, but remember
that a visually impaired child may be confused by different aspects
from a fully-sighted child.
Using tactile graphics in the classroom
A good tactile graphic is an excellent start
but a child will still need to be supported in its use. The following
seven-step procedure should help:
1. Check that the child is seated square
to the table to ensure consistent spatial orientation.
2. Anchor the graphic to the table to
prevent misunderstanding due to orientation changes.
3. Ask the child to 'sweep' the graphic
with both hands to get an overall idea of the graphic's size and
4. Briefly explain the purpose of the
5. Draw attention to any overall organisation
(e.g. a circular shape as in the water cycle).
6. Direct attention to specific parts,
explaining each in turn, and how it relates to other parts.
7. Allow the child to feel for themselves
- they will find this more informative than having their fingers
guided all the time.
We hope this brief introduction will give you
the confidence to have a go if you find yourself with a child
in your class who might benefit from tactile graphics. If you
want to know more, a very readable, classroom-oriented book is
Tactile Graphics in Education.
Sources of further information
RNIB Customer Services (Raised Diagram
Copying Service), P. O. Box 173, Peterborough PE2 6WS (Tel:
0345 023 1534).
Tactile Graphics in Education by Ron Hinton (Moray House
Publications, 1996). ISBN 0901 580 775
National Centre for Tactile Diagrams, www.nctd.org.uk (Tel:
01707 286 348).
This article was written as part of a research
programme aimed at improving access to graphics for visually impaired
children. The programme is funded by the Reginald Phillips Memorial
Trust and we would like to thank the trustees for their support.
We would also like to thank Sally Howell, Pauline Adams, Susie
McDonald and Helen Edwards for their time, interest and constructive
About the authors
Linda Sheppard and Frances Aldrich are research
psychologists at the University of Sussex, specialising respectively
in the study of memory, particularly how actions during learning
affect subsequent recall, and how design of materials affects
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